Apparatus is described in U.S. Pat. No. 3,230,615 issued Jan. 25, 1966 to Krengel et al. for producing thin-walled metal tubing from metal strip wherein the tubing is further treated by galvanizing and sizing. The continuous production of thin-walled metal tubing from metal strip has significantly reduced the cost of tubing, such as that commonly used as electrical conduit. The zinc layer provides resistance to corrosion and subsequent long life.
It has become increasingly popular in recent years to use metal tubing in decorative items such as art objects, lamps, furniture, etc. In such objects, tubing is generally used which has a lustrous or semilustrous finish to give an attractive appearance to the object. To this end, electroplated zinc, aluminum, chromium-plated tubing and stainless steel tubing are commonly used in indoor or outdoor furniture, lamps, toys, appliances, etc. However, the cost of such tubing is much higher than hot dip-metal coated tubing, such as galvanized tubing.
While hot dip metal coated tubing, such as galvanized tubing used as electrical conduit, has a rough functional surface appearance and is thus inappropriate for use in decorative items, such tubing may be polished to have an attractive lustrous finish appropriate for decorative use. In order to maintain the cost advantage that such tubing has over other decorative tubing, it is necessary that a decorative finish be given to the tubing as a part of the continuous forming line.
Accordingly, it is an object of this invention to provide apparatus where tubing is formed from metal strip and polished to provide a finish which is suitable for decorative use.